TCP/IP over STANAG 5066 HF packet Radio - Ham-pages ... No ...

1 

TCP/IP over STANAG 5066 

HF packet Radio 

Presented By: 

Jan-Willem Smaal 

Communications Systems Division / Radio Branch 

Voice: 31 70 314 2407 

Fax: 31 70 314 2176 

Jan-Willem.Smaal@nc3a.nato.int 

NATO UNCLASSIFIED

2 NC3A/CSD-R/JWS 

Presentation Overview 

• STANAG 5066 framework 

• Equipment 

• Characteristics 

• Subnet Clients 

• PPP subnet client (Annex F.9) 

• Characteristics 

• Implementation 

• IP subnet client (Annex F.10) 

• Implementation 

• Efficient IP Multicast support 

• Performance 

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HF transceiver 

HF modem 

HF antenna 

RF 

IF Audio 

STANAG 5066 Equipment 

Control 

STANAG 5066 controller 

Local Area Network 

Server 

running 

Subnet clients 

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Broadcast 


STANAG 5066 Subnet 

Service Characteristics 

• Transmission Modes: 

• ARQ (requires half/full-duplex transmission) 

• non-ARQ (uses simplex transmission) 

– with no detectable errors 

– with detected errors marked 

• Data Delivery Confirmation Modes: 

• none 

• Node-to-Node delivery (at subnetwork level) 

• Client-to-Client delivery 

• Delivery Order: 

• in the order submitted by the sending client 

• in the order correctly received by the receiving client 

• Minimum Number of Retransmissions 

• (non-ARQ transmission modes only) 

Point-to-Point 

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STANAG 5066 subnet clients 

• HMTP (HF Mail Transfer Protocol) �� Annex F.4 

• RFC-821 (SMTP) 

• RFC-2197 (Command Pipelining) 

• BFTP (Basic File Transfer Protocol) �� Annex F.7.3.1 

• PPP (Point to Point Protocol) �� Annex F.9 

• RFC-1661 (structure) 

• RFC-1662 (HDLC-like framing) 

• IP (Internet Protocol) �� Annex F.10 

• RFC-1112 (Internet Group Management Protocol) 

• draft-fenner-igmp-proxy-03.txt (IGMP proxy) 

• Etc… 

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PPP subnet client (Annex F.9) 

• Supports any protocol that may be carried by PPP (including 

IPv6). (�� IPCP) 

• Authentication (�� CHAP/PAP) 

• Compression (�� CCP) 

• Multi link PPP (�� MP) 

• Limitations … No efficient IP Multicast support 

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Flag 

0x7e 

PPP datagram and framing 

Addr 

0xff 

Control 

0x03 

Protocol Information CRC 

1 1 1 2 up to 1500 octets/bytes 

2 1 

Protocol 

0x0021 

Protocol 

0xc021 

Protocol 

0xc023 

Protocol 

0xc223 

Protocol 

0x8021 

Protocol 

0x00fb 

IP datagram 

Link Control Protocol (LCP) 

Password Authentication Protocol 

(PAP) 

Challenge-Handshake Authentication 

Protocol (CHAP) 

IP Network Control Protocol (NCP) 

Link compressed datagram 

Flag 

0x7e 

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Implementation of the PPP subnet client 

Received S_UNIDATA_INDICATION 

messages are decapsulated, the FCS on the 

ppp datagram is recalculated and 

asynchronous HDLC-like framing is added. 

The resulting asynchronous HDLC-framed byte 

stream is written to the stdin of the pseudo 

TTY. 

Add HDLC-like framing and 

recalculate FCS 

Decapsulate 

S_UNIDATA_INDICATION 

stdin 

/dev/ppp0 

PPP daemon 

fork 

Pseudo TTY 

TCP port 999 

Subnet Interface Sublayer 

The ppp daemon forks off a speudo TTY, 

PPP frames in HDLC-like framing will be 

read and written to and from stdin/stdout. 

stdout 

The ppp5066 program removes the HDLC-like 

framing from the stdout of the ppp daemon, 

encapsulates the ppp frame into an 

S_UNIDATA_DATA_REQUEST and submits it to the 

subnetwork using the socket subnet interface. 

Remove HDLC-like framing 

Encapsulate into 

S_UNIDATA_REQUEST 

...lower layers... NATO UNCLASSIFIED 

Drawing by: J-W Smaal 

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IP subnet client (Annex F.10) 

• IP datagram is encapsulated in a S_UNIDATA primitive. 

• Point to point IP configuration: using ARQ tx_mode. (although 

non-ARQ is also allowed). 

• IN-ORDER delivery or AS-THEY ARRIVE 

• “One to Many”, or “Many to Many” IP Multicast configuration: 

using non-ARQ tx_mode. 

• Class D IP addresses (IP Multicast) mapped to STANAG 5066 group 

addresses. 

• IN-ORDER delivery or AS-THEY ARRIVE 

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IP client design and implementation 

• Use of the TUN/TAP (Ethertap) interface on the Linux operating 

system. 

• No adjustments necessary to user-space configuration tools 

since it looks just like a normal ethernet device to the operating 

system. 

• The complete system acts as an “HF IP router” where the ‘tap0’ 

interface is the IP subnet client interface. 

• Why did we have to implement the IP client in user-space? 

• Support for other Operating Systems 

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Queue: inQ 

DeQueue 

Thread: 

EnQueue 


Thread: 

tapread() 

Function: 

ip_input() 

s5066_write() 

user-space 

STANAG 5066 

stack 

kernel-space 

user-space 

read() 

calls.... 

calls.... 

Function: 

ip_igmp_proxy() 

/dev/tap0 

calls.... 

Function: 

write() 

Thread: 

tapwrite() 

ip_output() 

calls.... 

Function: 

DeQueue 

ether_output() 

Queue: outQ 

EnQueue 

calls.... 

Thread: 

s5066_read() 

user-space 

STANAG 5066 stack 

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Transmitting end 

tapread() 

ip_input() 

s5066_write() 

Receiving end 

s5066_read() 

ether_output() 


Ethernet 

hdr 

S_UNIDATA 

REQ 

Filtering and address mapping 

payload 

(ETHERTYPE_ARP) 

Ethernet 

hdr 

IP TCP/UDP/... 

Ethernet 

hdr 

U_PDU 

payload 

(ETHERTYPE_IP) 

payload 


IP IGMP 


Mapping of 

IP Multicast 

to Ethernet 

Multicast 

Ethernet 

hdr 

payload 


IP PIMv2 


Ethernet 

hdr 

S_UNIDATA 

REQ 

payload 


IP TCP/UDP/... 

U_PDU 

Subnet MTU 

Mapping of 

IP Multicast 

to STANAG 

5066 group 

addresses. 

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IP Multicast forwarding 

PC with 'McastRecv' PC with 'McastRecv' PC with 'McastRecv' 

eth0 

LAN 

penguin1 

S5066: 10.0.0.6 

tap0 

LAN 

PIM-SM Multicast IP router forwards 

received Multicast traffic from tap0 to eth0 

(and vice versa). 

eth0 

kernelpanic 

tap0 

S5066: 10.0.03 

PC with 'McastRecv' 

PC's are running a simple IP 

Multicast receiver application 

S5066: 10.0.0.5 

tap0 

LAN 

penguin2 

eth0 

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“user-interface” of sending end 

[jw-smaal@kernelpanic src]$ su -c './hfmcast -b -n fieldworks2 -U 10.0.0.3 -M 

17.0.0.1 -B 17.0.0.255' 

Password: 

SISmcast (c)2000 by NATO C3 Agency, CSD Radio Branch 

Using tap device: /dev/tap0, IPv4 address: 10.1.1.69 MAC address: fe:fd:0:0:0:0 

S5066 unicast addr: 10.0.0.3 

S5066 multicast addr: 1.0.0.1(group) 

S5066 broadcast addr: 1.0.0.255(group) 

client: Connected to: fieldworks2.csdr.nc3a.nato.int:9999 

ETHERNET type : 800 (ip), source: FE:FD:00:00:00:00, dest: 00:00:00:00:00:00 

Filtered> IP version: 4, header length: 6, total length: 32, id: 41138, ttl: 1, 

source: 10.1.1.69, destination: 224.1.2.3, protocol: 2 (igmp), tos: 00000000b 

IGMP message type: Ver. 2 membership report, routing code: 0, group address: 

224.1.2.3 


Mcast> IP version: 4, header length: 5, total length: 51, id: 41139, ttl: 1, 

source: 10.1.1.69, destination: 224.1.2.3, protocol: 17 (udp), tos: 00000000b 


Filtered> IP version: 4, header length: 6, total length: 32, id: 41142, ttl: 1, 

source: 10.1.1.69, destination: 224.0.0.2, protocol: 2 (igmp), tos: 00000000b 

IGMP message type: Leave-group message, routing code: 0, group address: 224.1.2.3 

NATO UNCLASSIFIED


“user-interface” of receiving end 

[jw-smaal@penguin1 src]$ su -c './hfmcast -b -a 10.1.1.127 -m 255.255.255.0 -n 

fieldworks1 -U 10.0.0.3 -M 17.0.0.1 -B 17.0.0.255' 

Password: 

SISmcast (c)2000 by NATO C3 Agency, CSD Radio Branch 

executing: /sbin/ifconfig tap0 10.1.1.127 netmask 255.255.255.0 -arp 

Using tap device: /dev/tap0, IPv4 address: 10.1.1.127 MAC address: 0:ff:9b:ea:6a:90 

S5066 unicast addr: 10.0.0.3 

S5066 multicast addr: 1.0.0.1(group) 

S5066 broadcast addr: 1.0.0.255(group) 

client: Connected to: fieldworks1.csdr.nc3a.nato.int:9999 

s_unidata_indication: len 64, prio 1, dest sap_id 9, dest_node 1.0.0.1, 

non-ARQ (broadcast) tx_mode, src sap_id 9, src_node 10.0.0.5, 

sizeof_u_pdu 51 

ETHERNET type : 800 (ip), source: 50:66:00:00:00:00, dest: 01:00:5E:01:02:03 

IP version: 4, header length: 5, total length: 51, id: 41139, ttl: 1, source: 

10.1.1.69, destination: 224.1.2.3, protocol: 17 (udp), tos: 00000000b 

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Performance 

• 4253 bps TCP payload throughput @ 9600 1/2 duplex short 

interleaver 

• ~6 seconds ICMP echo/reply (ping) round trip time. 

• Non-ARQ versus ARQ impact on TCP performance being 

investigated. 

• IETF PEP (Performance Enhancing Proxies) 

• IETF PILC (Performance Implications of Link Characteristics). 

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TCP troughput @ 2400 bps 1/2 duplex 

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